Problem: Simplify the following expression: $a = \dfrac{5z}{3} + \dfrac{z}{6}$
In order to add expressions, they must have a common denominator. The smallest common denominator is the least common multiple of $3$ and $6$ $\lcm(3, 6) = 6$ $ a = \dfrac{2}{2} \cdot \dfrac{5z}{3} + \dfrac{1}{1} \cdot \dfrac{z}{6} $ $a = \dfrac{10z}{6} + \dfrac{z}{6}$ $a = \dfrac{10z +z}{6}$ $a = \dfrac{11z}{6}$